The wp3 default theme TwentyTen comes with a choice of header images, which can be selected from the dashboard.
To rotate these images to show randomly in the header, we can make use of the global array variable which stores all the default header image information: $_wp_default_headers.

The rest is easy: we build a function, which we later save in functions.php of TwentyTen, to pick a random image out of the available images:

A flexible way to add google adsense into posts and pages in your wordpress blog.
This appraoch uses shortcodes which are an underused technique of increasing the functionality of themes.
Through the formatting options in the shortcode, the text can flow around the adsense blocks similar as it would happen with inserted images.
Options for the alignment are ‘left’, ‘center’, ‘right’ – anything else will be treated as ‘none’.

The code that needs to be added to functions.php of the theme is shown below:
it is called in the text with: [ a d s e n s e f l o a t = ' l e f t ' ]